With the extensive commercialization of the wireless broadband network, the wireless video function is known by users gradually. High-speed data transmission links of the wireless broadband networks provide a guarantee for a wireless Access Terminal (AT) to transmit large traffic data. The AT has a function of acquiring video data and video data and can be connected to a Packet Core Network (PCN) through a Radio Access Network (RAN) so as to access a wireless broadband network system.
A wireless video conference system is developed on the basis of the wireless broadband network system. The network structure of the wireless video conference system is shown as FIG. 1, wherein the AT establishes a link with a conference control centre through the RAN, the PCN, and an Internal Protocol (IP) network; and the link can transmit media data and control information of a wireless video conference bidirectionally, wherein the media data include a video stream and an audio stream. The AT has the capacity of acquiring the media data; data are transmitted between the AT and the RAN through an air interface (for example, the UM) protocol and are transmitted between the PCN and the conference control centre through a Transmission Control Protocol/Internet Protocol (TCP/IP) protocol; and the conference control centre has a function of receiving and distributing a media data stream and inviting the AT to attend and leave a video conference through an air interface signalling.
The above-mentioned wireless video conference system realizes the conference between the ATs supporting wireless video. However, with the continuous promotion of user experience, users sometimes hope that the AT supporting wireless video can make a session with a common cluster terminal so as to keep pace with more abundant conference requirement. A conventional cluster system is shown as FIG. 2, wherein the data is transmitted between cluster terminals through a Base Station (BS), a cluster dispatch client (for example, a Push To Talk Dispatch Client, which is called PTT DC or PDC for short), a cluster dispatch server (for example, a Push To Talk Dispatch Server, which is called PTT DS or PDS for short) and an IP network; and the cluster terminal accepts the dispatch of the PDS. At present, since the cluster terminal cannot analyze the video stream transmitted by the wireless video conference and the cluster terminal and the AT supporting wireless video are not directly positioned in the same network, the session between the AT supporting wireless video and the common cluster terminal cannot be realized.